Super‐Toughened Heat‐Resistant Poly(lactic acid) Alloys By Tailoring the Phase Morphology and the Crystallization Behaviors

Abstract

The interfacial grafting copolymerization and the compatibility between poly(lactic acid) (PLA) and ethylene-vinyl acetate-glycidyl methacrylate elastomer (EVM-GMA) are adjusted by varying the blending temperatures. High temperature is favored to the grafting reaction between epoxy groups of the EVM-GMA and terminal groups of the PLA, resulting in better compatibility between the two components. Taking PLA/EVM-GMA (80/20) blend as an example, an increase in blending temperature from 175 to 230 C led to a 42.8% reduction in EVM-GMA particle size, and consequently 137.8% and 52.6% increases in elongation at break (Eb) and notched impact strength (NIS), respectively. In comparison, the Eb and NIS of PLA/EVM blends without any interfacial reaction deteriorated dramatically due to thermal degradation of the PLA at high(er) temperatures. Furthermore, the PLA/EVM-GMA blend prepared at 230 C possesses both excellent toughness (Eb > 60%, NIS > 60 kJ m −2 ) and high heat deflection temperature (>90 C) after annealing at 100 C. This work provides a new approach in designing highperformance biobased materials which may broaden the application range of PLA in engineering areas.Although reactive blending with elastomers has been reported as an effective method for toughening of PLA, the effect of blending temperature, that is, the extent of in situ grafting reactions on the mechanical properties of PLA/elastomer blends has rarely been studied. The higher the blending temperature is, the higher reaction extent and compatibilization between PLA and elastomer. However, it may also lead to thermal degradation of PLA matrix, which is not conducive to the final mechanical performances (e.g., tensile strength).Additional supporting information may be found in the online version of this article.

High-Performance Polylactic Acid Materials Enabled by TiO2–Polydopamine Hybrid Nanoparticles

“…26 However, such shortcomings, like high brittleness and low UV-shielding performance, to some extent limit its full access to some industrial applications in food packaging or other conditions. Many methods have been reported to overcome the inherent brittleness of PLA, including blending modification, 27,28 plasticization, 29 and copolymerization. 30 The blending method is very simple and efficient to increase the toughness and improve the UVshielding properties among them, 31 but the strength and the transparency of PLA are often sacrificed.…”

Highly Stretchable and Flexible Melt Spun Thermoplastic Conductive Yarns for Smart Textiles

“…Smart textiles have drawn increased attention from the academic researchers and industry people due to their high sensitivity, high flexibility, breathability, multitasking capability, availability, low cost, deformability and comfort [1][2][3][4][5]. Textiles can be conductive applying various methods including spinning [6][7][8][9], knitting [10], coating [11][12][13][14][15], screen printing [16], inkjet printing [17,18] and 3D printing [19][20][21][22]. Electrically conductive yarn is one of the most basic and essential components of smart textiles due to its light weight, high stretchability, elasticity, flexibility, and comfort [23,24].…”